A postage meter is a device that produces an imprint that is a substitute for both the postmark and postage stamp.
The FR code identifies the meter manufacturer: Friden
The letter O before a meter classification indicates that meter text includes “U.S. OFFICIAL MAIL.”
FR1
The USCS Postmark Catalog lists only one ship, USS Kitty Hawk (CV-63), as having used the Meter FR1 postmark.
FR2
OFR1
OFR2
The following postmarks are classified as Meter OFR2
OFR3
The following postmark is classified as Meter OFR3 (#504156) ZIP 96627.